oxidation of refractory minerals

PRESSURE OXIDATION OF REFRACTORY GOLD ORES: THE

The refractory nature of the concentrate requires a pressure oxidation (POX) step to oxidise the sulfide minerals and unlock the value metals. The oxidation of sulfides is a highly exothermic reaction. The energy generated by the reaction of the sulfide minerals is such that the autoclave temperature can exceed the 210 – 230°C operating

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Bio-Oxidation and Biocyanidation of Refractory Mineral ...

Bio-Oxidation and Biocyanidation of Refractory Mineral Ores for Gold Extraction: A Review October 2014 Critical Reviews in Environmental Science and Technology 45(15)

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Column bio-oxidation of low-grade refractory gold ore ...

The refractory gold ore with high arsenic and sulfur used in this study was obtained from Yuantong Mining Company, Inner Mongolia, China. The chemical composition of the raw gold ore is presented in Table 1. Fig. 1 (a) gives the X-ray diffraction diagram of the raw gold ore. The data showed that pyrite and arsenopyrite are the main sulfide minerals.

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Refractory Gold Ore Treatment Methods

Jul 14, 2016  Pressure oxidation (POX) remains a further option for the oxidation of refractory sulfides. Several projects have been recently constructed: the Killita Project in Finland, the Amursk Project in Russia, the Pueblo Viejo Project in the Dominican Republic, and the MOPU expansion at Lihir.

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Sulfide Minerals Bio-Oxidation of a Low-Grade Refractory ...

Column bio-oxidation of mineral with a particle size less than 10 mm at 60°C resulted in higher mineral decomposition, finer fractions and eventually higher sulfide oxidation than that at 30°C. Sulfide-S dissolution increased from 58% to 77% from 30°C to 60°C after 247 ds of bio-oxidation. Further investigation into microbial community ...

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Evaluation of Parameters in the Bio-Oxidation Process of ...

Bio-oxidation, as treatment of refractory ores that contain low grade of gold, offers an economic and sustainable alternative for this purpose. The objective of this research was to evaluate the effect of particle size, pulp density and concentration of inoculum and inducer (Fe +2) on the bio-oxidation of refractory gold minerals in order to ...

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Simultaneous sulfide oxidation and gold dissolution by ...

Aug 15, 2021  Pyrite and arsenopyrite are known to be the most common gold-bearing sulfide minerals in refractory gold ores. Traditionally, these minerals have been first oxidized by roasting, acidic pressure oxidation or bio-oxidation to release gold, after which the

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US5851499A - Method for pressure oxidizing gold

Provided is a method for treating refractory gold-bearing ores that have both sulfide material with which the gold is associated and from which the gold is difficult to separate and having organic carbonaceous material having an affinity for at least one of gold and a gold complex. The mineral material is pressure oxidized in the presence of a halogen-containing material in a manner to reduce ...

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Bio-Oxidation and Biocyanidation of Refractory Mineral ...

Bio-Oxidation and Biocyanidation of Refractory Mineral Ores for Gold Extraction: A Review October 2014 Critical Reviews in Environmental Science and Technology 45(15)

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Oxidation of a refractory gold concentrate using pressure ...

The gold group at SGS Minerals Metallurgy (Malaga, Western Australia) has conducted a test programme in which a refractory gold ore sample was beneficiated by bench-scale floatation to generate a bulk sulphide concentrate grading 10.6 g/t Au, 13.1% S, 11.4% Fe, 0.18% C and 2.36% As. Mineralogical analyses determined that gold in the ore was ...

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CHLORIDE HYPOCHLORITE OXIDATION AND LEACHING OF

For extraction of gold from the refractory ores in which gold is surrounded by sul-fide minerals, oxidative pretreatment of the ore is essential to oxidize the sulfides and expose gold. Pyrometallurgical oxidation by roasting is encountered with environmen-tal limitations; thus hydrometallurgical methods are preferred. These methods include

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Specific Refractory Gold Flotation and Bio-Oxidation ...

knowledge and understanding on the interplay between refractory ore-specific primary and secondary mineral phases, solution chemistry, and the particle-solution interfacial species, particle interactions, and chemical/electrochemical reactions which underpin the mechanisms and kinetics of the leaching process. How these factors interact synergisti-

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Evaluation of Parameters in the Bio-Oxidation Process of ...

Bio-oxidation, as treatment of refractory ores that contain low grade of gold, offers an economic and sustainable alternative for this purpose. The objective of this research was to evaluate the effect of particle size, pulp density and concentration of inoculum and inducer (Fe +2) on the bio-oxidation of refractory gold minerals in order to ...

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Method and apparatus for minimizing oxidation pitting of ...

WO-2008027482-A3 chemical patent summary.

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Effect of Pretreatment of Sulfide Refractory Concentrate ...

The majority of the refractory gold and silver occurs in occlusion in sulphides, then precious metal dissolution is possible by first oxidizing auriferous sulfide concentrate using sodium hypochlorite-sodium-hydroxide solution followed of pressure cyanidation of the oxidized concentrate, for the extraction of precious metals. This process was conducted and evaluated under cyanide and oxygen ...

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Biooxidation - BioMineWiki

"In refractory ores, small particles of gold are covered by insoluble sulfides impeding the contact between cyanide and gold. In this case, a pretreatment stage must be considered, such as pressure oxidation, chemical oxidation, roasting or bio-oxidation, the latter currently being

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Native oxidation resistance of Al20Nb30Ta10Ti30Zr10 ...

May 30, 2019  The native oxidation resistance of an Al 20 Nb 30 Ta 10 Ti 30 Zr 10 (at.%) refractory complex concentrated alloy (RCCA) was evaluated at 1000 °C in air. Oxidation tests revealed that the alloy exhibits linear oxidation kinetics out to 4 h of oxidation, with an adherence to parabolic, diffusion-controlled oxidation from 4 to 100 h.

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WO2017065621A1 - Hydrometallurgical process for the ...

The invention relates to the hydrometallurgical process for the recovery of gold from arsenical refractory minerals, which promote a more efficient recovery in comparison to the conventional processes. This process comprises two steps: i) once the gold concentrate (arsenopyrite and arsenical pyrite) is obtained, same passes through a regrinding step, with the addition of the oxidising reagent ...

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Heap Bio-oxidation of Sulfide Concentrates

Nov 15, 2017  Heap Bio-oxidation of Sulfide Concentrates. Low-cost oxidation pretreatment technologies are needed in order to economically extract precious metals from refractory sulfidic deposits as the world’s free-milling reserves are consumed. Already, more than one-third of the gold ore reserves in the United States are considered to be refractory.

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Pressure oxidation - Wikipedia

Pressure Oxidation is a process for extracting gold from refractory ore.. The most common refractory ores are pyrite and arsenopyrite, which are sulfide ores that trap the gold within them.Refractory ores require pre-treatment before the gold can be adequately extracted. The pressure oxidation process is used to prepare such ores for conventional gold extraction processes such as cyanidation.

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Succession of Acidophilic Bacterial Community During Bio ...

Oct 11, 2010  To optimize the rate of bio-oxidation to recover gold from sulfide minerals, it is important to understand the dynamic change of acidophilic bacteria involved in this process. In this study, a batch bio-oxidation experiment was set up to bioleach Au from refractory pyrite and arsenopyrite using a mixed acidophilic culture over the duration of ...

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Bioleaching review part B: SpringerLink

Oct 18, 2003  This review describes the historical development and current state of metals leaching and sulfide mineral biooxidation by the minerals industries. During the past 20 years commercial processes employing microorganisms for mineral recovery have progressed from rather uncontrolled copper dump leaching to mineral oxidation and leaching in designed bioheaps for oxidation of refractory gold

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Bio-Oxidation and Biocyanidation of Refractory Mineral ...

Oct 06, 2014  (2015). Bio-Oxidation and Biocyanidation of Refractory Mineral Ores for Gold Extraction: A Review. Critical Reviews in Environmental Science and

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Two-Step Oxidation of Refractory Gold Concentrates with ...

The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the two-step pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample.

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CHLORIDE HYPOCHLORITE OXIDATION AND LEACHING OF

For extraction of gold from the refractory ores in which gold is surrounded by sul-fide minerals, oxidative pretreatment of the ore is essential to oxidize the sulfides and expose gold. Pyrometallurgical oxidation by roasting is encountered with environmen-tal limitations; thus hydrometallurgical methods are preferred. These methods include

More

Specific Refractory Gold Flotation and Bio-Oxidation ...

knowledge and understanding on the interplay between refractory ore-specific primary and secondary mineral phases, solution chemistry, and the particle-solution interfacial species, particle interactions, and chemical/electrochemical reactions which underpin the mechanisms and kinetics of the leaching process. How these factors interact synergisti-

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Bacterial Oxidation of Refractory Sulfide Ores for Gold ...

Sep 27, 2008  Bacterial Oxidation of Refractory Sulfide Ores for Gold Recovery E. Börje Lindström Unit for Applied Cell and Molecular Biology, University of Umea, S-901 87, Umeå, Sweden , Eva Gunneriusson Department of Inorganic Chemistry, University of Umeå, S-901 87, Umeå, Sweden Olli H. Tuovinen Department of Microbiology, The Ohio State University ...

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(PDF) Specific Refractory Gold Flotation and Bio-Oxidation ...

Jan 19, 2021  The proposed gold extraction enhancement mechanism included disintegration of gold-encapsulating gangue mineral agglomerates, and elimination of

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Method and apparatus for minimizing oxidation pitting of ...

WO-2008027482-A3 chemical patent summary.

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Refractory Gold Technology

application of pressure oxidation for refractory gold ore treatment, at the McLaughlin Gold Complex in California, commissioned in 1985. Refractory Gold Technology Sherritt’s Refractory Gold Technology is used to recover gold from refractory sulphide feedstocks.

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Developments and innovations in bacterial oxidation of ...

Nov 01, 1991  The Bacterial Oxidation (BIOX®) process for the pre-treatment of refractory ores for gold recovery developed by Genmin, the mining division of Gencor, has been operating successfully at the Fairview Mine since October 1986. The continuous operation of a pilot plant at Genmin Process Research has resulted in further process developments to improve plant operating efficiencies. These

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Biooxidation - BioMineWiki

"In refractory ores, small particles of gold are covered by insoluble sulfides impeding the contact between cyanide and gold. In this case, a pretreatment stage must be considered, such as pressure oxidation, chemical oxidation, roasting or bio-oxidation, the latter currently being

More

Native oxidation resistance of Al20Nb30Ta10Ti30Zr10 ...

May 30, 2019  The native oxidation resistance of an Al 20 Nb 30 Ta 10 Ti 30 Zr 10 (at.%) refractory complex concentrated alloy (RCCA) was evaluated at 1000 °C in air. Oxidation tests revealed that the alloy exhibits linear oxidation kinetics out to 4 h of oxidation, with an adherence to parabolic, diffusion-controlled oxidation from 4 to 100 h.

More

Basic Iron Sulphate in Pressure Oxidation Processing

refractory gold sulphide hosts are arsenopyrite and pyrite, and in order to achieve acceptable gold recoveries, it is generally necessary to break down the host mineral chemically. This is done by roasting, bacterial oxidation or pressure oxidation . processes, in which the sulphide component of the host mineral is oxidized with oxygen to elemental

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Pressure oxidation - Wikipedia

Pressure Oxidation is a process for extracting gold from refractory ore.. The most common refractory ores are pyrite and arsenopyrite, which are sulfide ores that trap the gold within them.Refractory ores require pre-treatment before the gold can be adequately extracted. The pressure oxidation process is used to prepare such ores for conventional gold extraction processes such as cyanidation.

More

Microbial oxidation of gold ores and gold bioleaching ...

Jun 01, 1994  This paper reviews recent progress in the use of microorganisms tooxidize the sulfidic matrix in refractory gold ores (bio-oxidation) and to solubilize elemental gold (bioleaching). Arsenopyrite oxidation , Bioleaching , Biohydrometallurgy , Pyrite oxidation ,

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